The "Pandas has been in the lore for a long time pal." defense that I have seen several times now is so stupid as probably everyone knows about pandarians, maybe they have read about or done the barrens Q or seen the ingame Pandarian brewmaster pet or read about them in a WoW book or played WC3, they aren't exactly Tigons.

It does not make any difference if they have been in the lore for 3 centuries or not, the exp pack still gonna make half the playerbase quit, no doubt about it just look at the number of youtube dislikes.